6o FIELD AND FOREST. 



necessary to consider the object attained, and thus close the investi- 

 gations. ' ' 



Elaborate tables of the results were appended to these yearly reports, 

 showing the age at which seeds ceased to grow, when preserved in the 

 manner indicated. The following is a summary. 



From thre to five sowings were made of 150 to 600 seeds of each of 

 338 species representing 74 natural families. , In a few cases so much 

 seed was not to be had, and in some the number sown amounted to 

 several thousands. 



158 species ceased to germinate at less than 3 years. 



94 " " " 3 



57 " " " 4 to 8 



16 '' " " 8 to 21 



5 " " " 25 to 26 



5 '' " " 27 " 



2 " " " 43 " 



I " " " 43 '' 



Four species of Colutea, Ulex, Dolichos, Malva, and Ipomea appear 

 to have still retained their vitality at the conclusion of these experi- 

 ments. Besides the seeds collected by the committee, whose age was 

 known with certainty ; seeds obtained from the following sources 

 were also tried. Soil from the bed of a fresh -water lake of the terti- 

 ary epoch, containing elytra, scales and seeds of Ceratophyllu7?i ; 

 Maize from Peruvian graves; Wheat, Barley <S:c., from Egyptian cata- 

 combs; Seeds from an Egyptian shoe found at Thebes; 100 species 

 from Morison's herbarium, 136 years old ; 24 species from Sibthorp's 

 collection, 55 years old; and Melon seed, 26 years old, none of which 

 grew. 



In 1844, 303 packets of seeds were received from Sir W. J. Hooker, 

 of various ages, not exceeding 44 years. The experiments with this 

 collection gave the following results ; of 92 species, t^Z years old, 2 per 

 cent, grew; of 182 species, 21 years old, 2 per cent, grew; of 42 spe- 

 cies, 4 years old, 31 per cent. grew. The species which retain vitali- 

 ty the longest, were Coronilla, 42 years old, 25 sown, 17 grew ; Lida, 

 25 years old, 120 sown, 75 grew; Cassia, 26 years old, 20 sown, 17 

 grew; Croton, 21 years old, 50 sown, 30 grew ; Cassia, 26 years old. 



